32 research outputs found

    Interleukin-10 Production by T and B Cells Is a Key Factor to Promote Systemic Salmonella enterica Serovar Typhimurium Infection in Mice

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    Indexción: Scopus.Salmonella enterica serovar Typhimurium (S. Typhimurium) is a Gram-negative bacterium that produces disease in numerous hosts. In mice, oral inoculation is followed by intestinal colonization and subsequent systemic dissemination, which leads to severe pathogenesis without the activation of an efficient anti-Salmonella immune response. This feature suggests that the infection caused by S. Typhimurium may promote the production of anti-inflammatory molecules by the host that prevent efficient T cell activation and bacterial clearance. In this study, we describe the contribution of immune cells producing the anti-inflammatory cytokine interleukin-10 (IL-10) to the systemic infection caused by S. Typhimurium in mice. We observed that the production of IL-10 was required by S. Typhimurium to cause a systemic disease, since mice lacking IL-10 (IL-10-/-) were significantly more resistant to die after an infection as compared to wild-type (WT) mice. IL-10-/- mice had reduced bacterial loads in internal organs and increased levels of pro-inflammatory cytokines in serum at 5 days of infection. Importantly, WT mice showed high bacterial loads in tissues and no increase of cytokines in serum after 5 days of S. Typhimurium infection, except for IL-10. In WT mice, we observed a peak of il-10 messenger RNA production in ileum, spleen, and liver after 5 days of infection. Importantly, the adoptive transfer of T or B cells from WT mice restored the susceptibility of IL-10-/- mice to systemic S. Typhimurium infection, suggesting that the generation of regulatory cells in vivo is required to sustain a systemic infection by S. Typhimurium. These findings support the notion that IL-10 production from lymphoid cells is a key process in the infective cycle of S. Typhimurium in mice due to generation of a tolerogenic immune response that prevents bacterial clearance and supports systemic dissemination

    Addressing the disparities in dementia risk, early detection and care in Latino populations: Highlights from the Second Latinos and Alzheimer's Symposium

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    The Alzheimer's Association hosted the second Latinos & Alzheimer's Symposium in May 2021. Due to the COVID-19 pandemic, the meeting was held online over 2 days, with virtual presentations, discussions, mentoring sessions, and posters. The Latino population in the United States is projected to have the steepest increase in Alzheimer's disease (AD) in the next 40 years, compared to other ethnic groups. Latinos have increased risk for AD and other dementias, limited access to quality care, and are severely underrepresented in AD and dementia research and clinical trials. The symposium highlighted developments in AD research with Latino populations, including advances in AD biomarkers, and novel cognitive assessments for Spanish-speaking populations, as well as the need to effectively recruit and retain Latinos in clinical research, and how best to deliver health-care services and to aid caregivers of Latinos living with AD

    Exploring Species Limits in Two Closely Related Chinese Oaks

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    Background. The species status of two closely related Chinese oaks, Quercus liaotungensis and Q. mongolica, has been called into question. The objective of this study was to investigate the species status and to estimate the degree of introgression between the two taxa using different approaches. [br/] Methodology/Principal Findings. Using SSR (simple sequence repeat) and AFLP (amplified fragment length polymorphism) markers, we found that interspecific genetic differentiation is significant and higher than the differentiation among populations within taxa. Bayesian clusters, principal coordinate analysis and population genetic distance trees all classified the oaks into two main groups consistent with the morphological differentiation of the two taxa rather than with geographic locations using both types of markers. Nevertheless, a few individuals in Northeast China and many individuals in North China have hybrid ancestry according to Bayesian assignment. One SSR locus and five AFLPs are significant outliers against neutral expectations in the interspecific FST simulation analysis, suggesting a role for divergent selection in differentiating species.[br/] Main Conclusions/Significance. All results based on SSRs and AFLPs reached the same conclusion: Q. liaotungensis and Q. mongolica maintain distinct gene pools in most areas of sympatry. They should therefore be considered as discrete taxonomic units. Yet, the degree of introgression varies between the two species in different contact zones, which might be caused by different population history or by local environmental factors

    Oak canopy arthropod communities: which factors shape its structure?

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    Modelling soil organic carbon stocks in global change scenarios: a CarboSOIL application

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    39 pages, 7 figures, 5 tables, 67 references.Global climate change, as a consequence of the increasing levels of atmospheric CO2 concentration, may significantly affect both soil organic C storage and soil capacity for C sequestration. In this research we develop a methodology to predict soil organic C (SOC) contents and changes under global change scenarios. CarboSOIL model is a new component of the land evaluation decision support system MicroLEIS, which was designed to assist decision makers to face specific agro-ecological problems. CarboSOIL, developed as a GIS tool to predict SOC contents at different depths, was previously trained and tested in two Mediterranean areas: Andalusia (SW Spain) and Valencia (E Spain). The model was applied under different IPPC scenarios (A1B, A2 and B1) according to different global climate models (BCCR-BCM2, CNRMCM3 and ECHAM5) and output data were linked to spatial datasets (soil and land use) to quantify SOC stocks. CarboSOIL model has proved its ability to predict the short-, medium and long-term trends (2040s, 2070s and 2100s) of SOC dynamics and sequestration under projected future scenarios of climate change. Results showed an overall trend towards decreasing of SOC stocks in the upper soil sections (0–25cm and 25–50 cm) for most soil types and land uses, but predicted SOC stocks tend to increase in the deeper soil section (50–75 cm). Soil types as Arenosols, Planosols and Solonchaks and land uses as “permanent crops” and “open spaces with little or no vegetation” would be severely affected by climate change with large decreases of SOC stocks, in particular under the medium-high emission scenario A2 by 2100. The information developed in this study might support decision-making in land management and climate adaptation strategies in Mediterranean regions and the methodology could be applied to other Mediterranean areas with available soil, land use and climate data.Peer reviewe

    The impact of the farming, abandonment and agricultural intensification on loss of water and soil. the example of the northern slopes of the Serra Grossa, Eastern Spain

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    [EN] Land abandonment throughout the twentieth century led to an intense landscape transformation in the mountain areas of the Iberian Peninsula. In some cases, and after 50 years of abandonment, agriculture returned with the development of commercial farms and the intensification of the agrarian activities. In the Easter Iberian Peninsula, following the abandonment of olive groves, vineyards and cereals during the 50’s, has been in the past two decades the expansion of intensive citrus production on sloping terrain. Geomorphological transects and simulated rainfall experiments have quantified the impact of traditional rainfed cultivation of the 50’s, abandonment, and the intensification of farming on the processes and landforms of erosion on the northern slopes of the Serra Grossa, south of the province of Valencia. It was found that the citrus groves have the highest number of rills and gullies. These erosive morphologies were not in the traditional crop tillage, and when they formed in the abandoned fields were soon controlled by the growth of vegetation. The abandonment of the crops reduced the soil losses, but the intensification of the agriculture with the citrus production has accelerated the soil erosion rates that exceed by several orders of magnitude (x4) the soil erosion rates measured during the abandonment and multiply by 17 the quantified traditional rainfed agriculture soil losses. Tillage of traditional rainfed orchards reduced runoff, but increased the concentration of sediments of the surface wash.[ES] El abandono del campo a lo largo del siglo XX supuso una intensa transformación paisajística en las zonas de montaña en toda la Península Ibérica. En algunos casos, y tras 50 años de abandono, la actividad agrícola ha regresado con explotaciones comerciales y con una intensificación de la actividad agrícola. En el Este Peninsular, tras el abandono de olivares, viñedos y cereales, se ha producido en las dos últimas décadas la expansión de la citricultura intensiva en ladera. Mediante transectos geomorfológicos y experimentos con lluvias simuladas se ha cuantificado el impacto del cultivo tradicional de secano de los años 50, el abandono y posterior recuperación, y la intensificación de la explotación agrícola sobre los procesos y formas de erosión en la vertiente norte de la Serra Grossa, al sur de la provincia de Valencia. Se ha comprobado que los campos de cítricos presentan el mayor número de regueros y cárcavas. Estas morfologías erosivas no existían en el cultivo tradicional por el laboreo, y cuando se formaron en los campos abandonados pronto fueron controlados por el crecimiento de la vegetación. El abandono de los cultivos redujo la pérdida de suelo, pero la citricultura intensiva ha vuelto a reactivar los procesos erosivos hasta tasas que superan en varios órdenes de magnitud el abandono (x4) y que multiplican por 17 las cuantificadas en la agricultura tradicional de secano. El laboreo del secano tradicional reducía las escorrentías, pero aumentaba la concentración de sedimentos de la arroyada.Los proyectos CGL2008-02879/BTE y LEDDRA 243857 financiaron esta investigaciónCerdà, A.; Giménez Morera, A.; Burguet, M.; Arcenegui, V.; González Peñaloza, FA.; García Orenes, F.; Pereira, P. (2012). El impacto del cultivo, el abandono y la intensificación de la agricultura en la pérdida de agua y suelo, el ejemplo de la vertiente norte de la Serra Grossa en el este Peninsular. Cuadernos de Investigación Geográfica. I(38):75-94. https://doi.org/10.18172/cig.1276S7594I3

    Climate change impacts on carbon stocks of Mediterranean soils: a CarboSOIL model application

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    Comunicación oral presentada en la Sesión: SSS9.11: Soil erosion and desertification processes in Mediterranean areas.-- Congreso celebrado del 7-12 abril 2013, en Viena, Austria.The Mediterranean area is among the most sensible regions to climate change and large increases in temperature as well as drought periods and heavy rainfall events have been forecasted in the next decades. Soil organic C (SOC) prevents from soil erosion and desertification and enhances bio-diversity.Peer reviewe

    VVV DR1: The first data release of the Milky Way bulge and southern plane from the near-infrared ESO public survey VISTA variables in the Vía Láctea

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    Context. The ESO public survey VISTA variables in the Vía Láctea (VVV) started in 2010. VVV targets 562 sq. deg in the Galactic bulge and an adjacent plane region and is expected to run for about five years. Aims. We describe the progress of the survey observations in the first observing season, the observing strategy, and quality of the data obtained. Methods. The observations are carried out on the 4-m VISTA telescope in the ZYJHKs filters. In addition to the multi-band imaging the variability monitoring campaign in the Ks filter has started. Data reduction is carried out using the pipeline at the Cambridge Astronomical Survey Unit. The photometric and astrometric calibration is performed via the numerous 2MASS sources observed in each pointing. Results. The first data release contains the aperture photometry and astrometric catalogues for 348 individual pointings in the ZYJHKs filters taken in the 2010 observing season. The typical image quality is ~ 0.9-1.0. The stringent photometric and image quality requirements of the survey are satisfied in 100% of the JHKs images in the disk area and 90% of the JHKs images in the bulge area. The completeness in the Z and Y images is 84% in the disk, and 40% in the bulge. The first season catalogues contain 1.28 × 108 stellar sources in the bulge and 1.68 × 108 in the disk area detected in at least one of the photometric bands. The combined, multi-band catalogues contain more than 1.63 × 108 stellar sources. About 10% of these are double detections because of overlapping adjacent pointings. These overlapping multiple detections are used to characterise the quality of the data. The images in the JHKs bands extend typically ~4 mag deeper than 2MASS. The magnitude limit and photometric quality depend strongly on crowding in the inner Galactic regions. The astrometry for Ks = 15−18 mag has rms ~35−175 mas. Conclusions. The VVV Survey data products offer a unique dataset to map the stellar populations in the Galactic bulge and the adjacent plane and provide an exciting new tool for the study of the structure, content, and star-formation history of our Galaxy, as well as for investigations of the newly discovered star clusters, star-forming regions in the disk, high proper motion stars, asteroids, planetary nebulae, and other interesting objects.Peer reviewe

    EBV, HCMV, HHV6, and HHV7 Screening in Bone Marrow Samples from Children with Acute Lymphoblastic Leukemia

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    Acute lymphoblastic leukemia (ALL) is the most common cancer in childhood worldwide and Mexico has reported one of the highest incidence rates. An infectious etiology has been suggested and supported by epidemiological evidences; however, the identity of the involved agent(s) is not known. We considered that early transmitted lymphotropic herpes viruses were good candidates, since transforming mechanisms have been described for them and some are already associated with human cancers. In this study we interrogated the direct role of EBV, HCMV, HHV6, and HHV7 human herpes viruses in childhood ALL. Viral genomes were screened in 70 bone marrow samples from ALL patients through standard and a more sensitive nested PCR. Positive samples were detected only by nested PCR indicating a low level of infection. Our result argues that viral genomes were not present in all leukemic cells, and, hence, infection most likely was not part of the initial genetic lesions leading to ALL. The high statistical power of the study suggested that these agents are not involved in the genesis of ALL in Mexican children. Additional analysis showed that detected infections or coinfections were not associated with prognosis
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